Hello every one, been lurking here for some time but finally need eveyones help.
I bought a 2006 H3 with 87k on the odometer. Had it for a little over a two monhs now and absolutely LUV this thing.
Anyway, seemsit has developed and intermittent rough idle over the last two weeks since I have been out of town on bussiness.
Got home and took it for a ride today and sure enough, confirmed what my wife told me. Initially the rough idle was very mild and
intermittent. Noticeable under 1500RPM's and smoothed out afterwards. No check engine light present and no error codes stored
after having it checked at Autozone.
I decided to try and throw some plugs into the car and became aware of my 1st problem. Bought all new Autolite Platinum Plugs
(AP 5263) and could not find the Gap setting for these plugs, or any other plugs off the internet. Had to assume that they where
pre-gapped and checked them at .045 to .046 Checked the original plugs and they appear to be gapped the same. The original
plugs are AC Delco 41-981 12599232 and they all appear to be burning clean. Replaced with new Autolite Platinum and H3 and
now seems to have the same rough idle, maybe more pronounced. After a 5 min test drive the CEL finally came on and I drove to
Autozone where they where able to confirm "Cyl 2 miss fire" I decided to buy a new Coil-Ignition for #2cyl and it turns out they have
nothing listed/available for the H3.
We looked up the same part for a 3.5L Colorado engine and it shows OEM PN# 8-12568-062-0 The one they sell is made by Duralast
PN# C1395 $62.99 My 1st question is if these two parts are the same for the H3 and the Colorado?
My 2nd question is more drawn out........ Why did the CEL not come on with the original plugs when it was obvious there was a missfire?
I am aware of the bad Cyclinder heads with poorly heat treated valve guides but this vehicle has 87k on it? also if it where a bad valve guide
would it not have a consistent rough idle at any RPM and wouldnt the #2 Cyl Spark plug be some what fowled compared to the others?
I am afraid to take the vehicle into the Dealer because I hate to be lumped into some " Ah yea, they had a batch of bad cylinder heads,
that will cost you $3000.00 thanks"
Wanted to do a Compression check but not even sure how to do that on this car since the plugs are under the air box. Not even sure what
the compression values should be? I am hoping that all I have to do is replace the Coil ignition with the same part as the one
for the Colorado but I would hate to buy the wrong part and cause myself even more confusion?
If the MAS was dirty the idle would be erratic but not feel like a miss fire? If the Throttle body was dirty and sticking then I would feel a hesitation
while accelerating and the idle would stay high while decelerating which is not the case.....
any input or feed back would be GREATLY appreciated.......if it turns out to be the head.......well I am gonna have to buy a new head and install myself
since there is no way I can afford $3kto $4k........
Any ideas on where I can find original parts etc would also be appreciated.
Thanks in advance for any ideas/thoughts/suggestions. Ken